The closest thing we actually got to a foldable phone from Samsung in 2013 was the Samsung Galaxy Round. This was far from the prototypes and concepts wed seen, but as the worlds first curved screen smartphone it was a big step in the right direc...

Samsung releases S3 in 2012. S2 in 2011. While the first iPhone with the name S is the 5S in 2013. So what's your point? If you're saying about Plus then yes iPhones used it first with 6Plus followed by Galaxy S6 Plus. But definitely not the name S.